Numerical Modeling of Multi-Aperture Frequency Selective Surfaces with the Pairs of U-Shaped Slots

Numerical modeling data for the frequency selective surfaces whose elementary period contains one or two pairs of U-shaped slots are presented in the paper. A peculiarity of the numerical model implementation is discussed. In order to make the calculations rapid, a virtual waveguide is incorporated into the module that is responsible for the calculation of the scattering matrix of a plane junction of the Floquet channel and U-shaped waveguides. Numerical examples are given for a single-standing perforated screen and a two layer frequency selective surface. A possibility to generate a transmission response by the help of the resonant coupling via the first higher (not fundamental) mode of U-shaped slots is demonstrated.